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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.internal.jimage;

import java.nio.ByteBuffer;
import java.nio.ByteOrder;
import java.util.Arrays;
import java.util.Objects;

Implementation Note:This class needs to maintain JDK 8 source compatibility. It is used internally in the JDK to implement jimage/jrtfs access, but also compiled and delivered as part of the jrtfs.jar to support access to the jimage file provided by the shipped JDK by tools running on JDK 8.
/** * @implNote This class needs to maintain JDK 8 source compatibility. * * It is used internally in the JDK to implement jimage/jrtfs access, * but also compiled and delivered as part of the jrtfs.jar to support access * to the jimage file provided by the shipped JDK by tools running on JDK 8. */
public class ImageStream { private ByteBuffer buffer; public ImageStream() { this(1024, ByteOrder.nativeOrder()); } public ImageStream(int size) { this(size, ByteOrder.nativeOrder()); } public ImageStream(byte[] bytes) { this(bytes, ByteOrder.nativeOrder()); } public ImageStream(ByteOrder byteOrder) { this(1024, byteOrder); } public ImageStream(int size, ByteOrder byteOrder) { buffer = ByteBuffer.allocate(size); buffer.order(Objects.requireNonNull(byteOrder)); } public ImageStream(byte[] bytes, ByteOrder byteOrder) { buffer = ByteBuffer.wrap(Objects.requireNonNull(bytes)); buffer.order(Objects.requireNonNull(byteOrder)); } public ImageStream(ByteBuffer buffer) { this.buffer = Objects.requireNonNull(buffer); } public ImageStream align(int alignment) { int padding = (getSize() - 1) & ((1 << alignment) - 1); for (int i = 0; i < padding; i++) { put((byte)0); } return this; } public void ensure(int needs) { if (needs < 0) { throw new IndexOutOfBoundsException("Bad value: " + needs); } if (needs > buffer.remaining()) { byte[] bytes = buffer.array(); ByteOrder byteOrder = buffer.order(); int position = buffer.position(); int newSize = needs <= bytes.length ? bytes.length << 1 : position + needs; buffer = ByteBuffer.allocate(newSize); buffer.order(byteOrder); buffer.put(bytes, 0, position); } } public boolean hasByte() { return buffer.remaining() != 0; } public boolean hasBytes(int needs) { return needs <= buffer.remaining(); } public void skip(int n) { if (n < 0) { throw new IndexOutOfBoundsException("skip value = " + n); } buffer.position(buffer.position() + n); } public int get() { return buffer.get() & 0xFF; } public void get(byte bytes[], int offset, int size) { buffer.get(bytes, offset, size); } public int getShort() { return buffer.getShort(); } public int getInt() { return buffer.getInt(); } public long getLong() { return buffer.getLong(); } public ImageStream put(byte byt) { ensure(1); buffer.put(byt); return this; } public ImageStream put(int byt) { return put((byte)byt); } public ImageStream put(byte bytes[], int offset, int size) { ensure(size); buffer.put(bytes, offset, size); return this; } public ImageStream put(ImageStream stream) { put(stream.buffer.array(), 0, stream.buffer.position()); return this; } public ImageStream putShort(short value) { ensure(2); buffer.putShort(value); return this; } public ImageStream putShort(int value) { return putShort((short)value); } public ImageStream putInt(int value) { ensure(4); buffer.putInt(value); return this; } public ImageStream putLong(long value) { ensure(8); buffer.putLong(value); return this; } public ByteBuffer getBuffer() { return buffer; } public int getPosition() { return buffer.position(); } public int getSize() { return buffer.position(); } public byte[] getBytes() { return buffer.array(); } public void setPosition(int offset) { buffer.position(offset); } public byte[] toArray() { return Arrays.copyOf(buffer.array(), buffer.position()); } }